Fluid pressure valve



H. W. TREVASKIS FLUID PRESSURE VALVE Aug. 4, 1953 3 Sheets-Sheet l Filed March 10, 1948 Aug 4, 1953 H. w. TREvAsKnS 2,647,535

FLUID PRESSURE VALVE Filed March l0, 1948 3 Sheets-Sheet 2 Aug- 4, 1953 H. w. TREvAsKIs FLUID PRESSURE VALVE 3 Sheets-Sheet 3 Filed March 10, 1948 El. L

Patented Aug. 4, y1953 FLUID PRESSURE VALVE Henry William Trcvaskis, Solihull, England, as-

signer to Dunlop Rubber Company Limited, London County, England, a British company Application March 10, 19428, Serial No. 14,032 En Great Britain March 13, 1947 7 Claims.

i` This invention relates to fluid pressure valves of the type used for controlling the movement of mechanism` disposed remote from the pressure valve, and, more particularly, for controlling a pneumatically or hydraulically operated mechanism that is `adapted to control the movement of aircraft undercarriages, flaps or the like.

Fluid pressure valves of the above type should be capable of admitting fluid pressure to the mechanism that operates the undercarriages or the like of aircraft, of ensuring that the fluid pressure is maintained therein as long as may be desired, and of vpermitting the :duid pressure to escape when desired. Each pressure valve therefore has virtually three chambers, one chamber in communication with the source of duid supply, a second or operating chamber in communication with the mechanism that operates the undercarriages or the like, and a third or exhaust chamber. IThere must be an inlet valve to permit l fluid pressure to pass from the first to the second chamber and an exhaust valve to permit the liuid pressure to pass from the second chamber when it is no longer required. Both valves should not of course be open at the same time.

It is already `known. to provide a uid pressure valve for brakes and the like having three chambers, a supply chamber in communication with a source of fluid pressure supply, an operating chamber in communication with for example a braking circuit and an exhaust chamber. Sometimes the inlet valve and exhaust valve are two independent parts and sometimes they are coaxial and substantially move together. In the latter case an operating member co-axial with the valves forms a seating for the exhaust valve, and by the interposition of springs it can be ensured that the movement of the operating member in one direction first closes the exhaust valve before the inlet valve opens and the movement in the opposite direction first closes the inlet valve before the exhaust valve opens. It is known `to apply an axial load to the operating member in order to eiect the desired movements of the valves but the consequential levers occupy much space. Such constructions are therefore not suitable when space and weight considerations are of primary importance, and are even less suitable when it is desired to control selectively the operation of a mechanism which is adapted to control the movement of two or more other mechanisms.

It is an object of this invention to provide a uidpressure valve of the type having supply, operating, and exhaust chambers and co-axial 2 inlet and exhaust valves which is compact in size and light in weight.

it is a further object of this invention to provide a iiuid pressure valve which may be employed selectively to operate a mechanism which is adapted to control the movement of two or more other mechanisms.

According to the present invention `a Huid pressure valve for the remote control of mechanism of the type having supply, operating, and exhaust chambers, co-axia'l inlet and exhaust valves, and an operating member co-axial with the said valves forming a seating for the said exhaust valve comprises an angularly displaceable member adapted to move the said operating member axially, and a rocker shaft adapted to actuate the said angularly displaceable member.

Preferably two such valve units are associated together and have a rocker shaft in common to constitute a control valve suitable, for example, for a double-acting jack adapted to control the movement of the undercarriages, flaps or the like of aircraft. If four such valve units are associated together and suitably adapted they constitute a fluid pressure valve suitable for a double-acting jack having two co-axial cylinders each provided with a piston and piston rod.

In order that the invention may be more clearly understood and carried into effect the same will now be more particularly described with reference to the accompanying drawings in which:

Fig. l is a plan view of a uid pressure valve suitable for selective control of a twin-cylinder double-acting jack which has two co-axial cylinders each provided with a piston and piston rod.

Fig. 2 is a sectional side View of Fig. 1 on the lines A-A and on a smaller scale illustrating the rocker shaft in its mid-position.

Fig. 3 shows diagrammatic representations at a, b, c and d, of the angularly displaceable members and associated parts with the rocker shaft in its mid-position.

Fig. 4 shows diagrammatic representations at a2 and a3 of the angularly displaceable member shown in Fig. 3a but in its other positions.

Fig. 5 is a side view of an alternative formof angularly displaceable member.

Referring to Figs. l to 4 the pressure valve has a base or housing l in which is rotatably mounted a longitudinally disposed rocker shaft 2 adapted for manual operation external of the housing at 3 by handle means indicated at 45' (Figure 3) and, at four equi-spaced positions a, b, c, d, along its length, having eccentric formations 4a, 4b, 4c, 4d, which are located in a cavity 5 formed in said housing. Each eccentric is circular in cross-section and its diameter is approximately equal to half the diameter of the rocker shaft and two eccentrics la and iid are disposed opposite each other on one diametrical axis andr the) other two eccentrics ib and de are disposed opposite each. other on another diametrical axis and the two axes are angularly spaced apart at 45.

Four pockets Ea, 6b, v6c and 6d are formed. in the housing and extend from the cavity and open on one face of said housing and said face has apn plied to it a cover plate l'. The pockets are each provided by a base 8, and. endwallv 9` and two parallel side walls IU and said pockets are spaced. Iapart to coincide with the eccentrics on: the shaft and adjacent pockets are disposed on opposite sides of said shaft. In the respective pockets are flat plate-like angularly displaceable members Hw, Hb, Mc andi Hd the plane cf each of which is disposed at right angles to the. axis ofthe shaft. The angularly displaceable members. and. parts associated therewith are substantially identical at: each, position andl therefore, as. far as is appropriate, the angularly displaceable member Ila and its associated parts will be described with reference to. Figs.' 1 and 2; as being reprei sentative. except where. otherwise stated.

The angularlydisplaceable member im is bifurcated at. its one end toforma slot Iza which is` engagedy by the eccentricv da intermediate the ends ofz'saidangularly displaceable member. The bifurcation provides twobranches i3d and Ida which. are disposed; longitudinally. of. the angula-rly displaceable member. and the branch ma is longer. than. the branch. 13a. and; constitutes an operating branch. to behereinafter referred to. Thatiendi of. the angularly displaceable member remotefrom. theslot'- has a nger l5a disposedv paralleland substantially opposite to-th'e operatingv branch. Ilia. andthe edge of said angularly. displ'acea-blelmember formedlby. the branch i3d has a nger Ita, saidfingers extending` in. the plane.of1theangularly. displaceable member. Oppos-itethe finger Ita the angularly displaceable member.- has-.a corner lila; The end-Enger ld abuts against the endlwall 9, theedge finger I 6a abuts againstf-the'cover plate 'if and-the corner- HILl abuts against the base 8;' The angularly.- displaceable member. is therefore supported within the side walls i0 of the respective pocket, at its Slots 12a, andpnitsperiphery at the extremities of its tWo fingers |5111 and Ia andat' the .cornerv lfm.

Onthe-opposite side-of` theshaft 2 to the pocket SasisA a` hollow cylinderl'afthe axis of which is disposedparallel torthe` plane of the angularlydisplaceable member'and substantially at rightl anglesto .the axis of the slot i2a. The wall of the hollow cylinder. ih formed.withanaperture [9a adjacent the'upper-endof the-tube and with another aperture at approximately-'the middle.

ofisaid tube'and, regarding the angularlydispla'ceablememberl I'la; the aperture 20a is engaged by. theoperating branch Ida. The hole.

adjacent :its .otherA end and said Washersurrounds'i 755:

= erating chamber.

the hollow cylinder and this end of the bush abuts against an annular sealing washer 24a against which is applied a metal washer 25a, said sealing and metal washers being the same external diameter as the diameter of the bore 26a. A rst spacing tube 2id, the wall of which is perforated, is disposed co-axial withk and is of' smaller diameter than the bore, andk saifd tubel abuts at one end against the metal washer 25a and at its other end against one face of a valve-seating ring 28a whose periphery has an annular seal 23a and ts the bore. The chamber formed in said bore between the metal washer and the valve-seating ring` will hereinafter be referred to as the op- The other face of the valveseating ring abuts against one end of a second spacing tubeV Sd the wall of which is perforated and the other end of which abuts against the end face 31a of the bore which, at this end, is of a diameter larger than the diameter of the second spacing tube for a length less than the length of said tube, and the chamber formed between the end of theboreand the adjacent face of the valve-seating ring will hereinafter be referred to as the supply chamber.

An inlet duct 32 isadapted'to be connected to a supply sourcev of duid pressure by a union` 33 andv saidduct'is formedv in' the housingto extend parallel with and below'v the shaft. The duct is in. communication with the four' supplyv chambers of which adjacent chambers aref disposed on oppositesides ofv thedlct.

Ifwo disc-like valve heads4 34u' and 35a are axially spaced apart andare mounted'. on a stem 36a to forman. integral unit which is Co-axial with the hollow cylinden. and saidstem passes through, andisof smaller diameter than an axial passage 31a inthe valve-seatingV ring, whereby the head 34a, hereinafter referredlto` asthe'exlia'ustl valve head; is disposediwithin theoperating.' chamber to `c0operatel with one end ofA the' hollow cylinder and'to-slide within andbesup= ported' byA therst spacing'tube 3M, while the other head 35a; hereinafter referredI to as the inlet valve head; is'- disposed withinv the supply chamber to co`operate witha seating' 38a formed on thei-adjacentside off'thevalve-seating ring. A spigot' 38d` extends fromfthe face offtlie inlet.' valve head* opposite that face which* cooperates. with the valve' seat andlsaid spigot sup'- ports one end of1a= coile'd'compression'. spring 40kt whose other end'is located in'lalsocket Ha-formed' in theA housing-'- ati-thel closedfendof the bore;l

Four passages 42m-42h, 42e andddf are formed? inthe housing and'leach-passage communicates witha differenti one of Vthe four; operating: cham-I bersand each-passage` leadstoonei of four unions'- 4311, 431),. 43e and 43d? each.L adaptedf to becon'- nected'to :the ja'ckt.

As showninlig. 3 the angularly.vr displaceable' members. lia; Il bbearsi at theirrehpective corners. Ilm. lili-on. the. bas'eIB?. of.' the respective` pockets'. i9; andi their. operatng branches". |4a,=. itbengage theapertureslta; 2th" respectively.

- The: angularly displaceableI mem-bers'- Ilc, IId.x

bear. at. their respective fingers: I'5c,.l6donithe base 8 i of the frespective pockets'zl il; :and-theiri op erating branches.' Hic; |427engagetheiapertures l 9c; I alfrespectively. The: Ahandle: meansfrll'ifandl rocker. shaft 2i are 1shown in mida-position andtllc1 inlet. valves 35a, 35Z1=areioperr-whilsttthefinlet: valves 35e, 35d are closed.

rockedIthrough an. angle of 45i'in aclockwisef direction from itsrmid'position. andino rri'o'v'errientV of the `angularly dsplaceable member occurs vso that the inlet valve remains. open while the exhaust valve remains closed, whereas in (a3) (Fig. 4) said rocker shaft has been rocked through an angle of 45 in an anti-clockwise direction from its mid-position thus mo-ving the angularly dsplaceable member so that the inlet valve is closed while the exhaust valve is opened.

A pointer 46 is secured to the rocker shaft to indicate the angular position of said shaft and said pointer is provided with a stop peg (not shown) which eng-ages Ian arcuate groove in the housing.

In an alternative form of the invention a pressure valve as above described is provided but has angularly dsplaceable members as illustrated in Fig. 5. Each of said members having a short side finger 44 opposite the side finger I6.

In operation, by rocking the shaft each hollow cylinder can be moved by its respective angularly dsplaceable member to either of two extreme positions, in one position said hollow cylinder abuts against the exhaust valve head to close the end of said cylinder and to maintain the inlet valve head off its seat against spring action thereby to allow fluid pressure to pass from the supply chamber to the operating chamber and via the respective passage to the jack, and in the other position said hollow cylinder is withdrawn in a direction away from the inlet valve seat whereby the compression spring moves the inlet valve hend onto said seat and the exhaust valve head makes an equal movement which is less than the movement of the hollow cylinder so that the fluid pressure passes back into the operating chamber from the jack and through the bore of the hollow cylinder to the cavity which constitutes an exhaust chamber and is in communication with a union nozzle 44 external of the housing.

The relative positions of the eccentrics and the slots in the respective angularly displeacable members is such that for each of the three angular positions of the rocker shaft different combinations of two inlet valves are open and two exhaust valves closed.

It should be appreciated that while the pressure valve above described has four valve units each of which comprises inlet and exhaust valves, a hollow cylinder, and an angularly displacable member, a pressure valve having one or any other number of such units is also within the scope of the invention.

Having described my invention, what I claim 1s:

1. A fluid pressure valve for the remote control of mechanism having supply, operating and exhaust chambers, co-axial inlet and exhaust valves, a recessed operating member co-axial with the said valves forming a seating for the said exhaust valve, a rocker shaft formed with an eccentric having a cross section smaller than that of said shaft, an angularly dsplaceable member positioned to move the said operating member axially, said angularly dsplaceable member being bifurcated at one extremity to form a slot to engage said eccentric, and to form a branch extending to engage the recess of said operating member, said dsplaceable member having at least two projecting fingers at the extremity opposite said bifurcation positioned to contact the walls of said exhaust chamber whereby the angularly dsplaceable member rocks relative to the walls of the exhaust chamber when actuated by the said rocker shaft and moves the said movable member axially.

2. The uid pressure valve of claim 1 in'which the rocker shaft is rotatable between three positions and the said eccentric is so positionedrelative to the said slot that rocking of the vshaft between the mid-position and one adjacent position operates the valves while rocking between the mid-position and the other position does not operate the valves.

3. A fluid pressure control mechanism comprising a housing having two valve mechanisms each comprising supply, operating and exhaust chambers, a valve seat between said supply and operating chambers, a hollow longitudinally slidable operating member having a recess formed therein, a passage through said operating member connecting said operating and exhaust chambers, a pair of connected valves co-axial -with and movable by said operating member, one: of said valves on the operating side of said valve seat being positioned to be contacted by said operating member to close said passage andthe other valve being movable from said valve seat on further movement of said operating member, an angularly displaceable member biurcatedat oneextremity to form a slot, one branch of said bifurcated member being extended to iit into the recess in said longitudinally slidable operating member, said two valve members being arranged in side by the side relationship and a common rocker shaft provided with two eccentrics, one for each said bifurcated member to engage the slot of said bifurcated member to actuate said bifurcated members of said valve mechanism.

4. A fluid pressure mechanism as defined in claim 3 in which said angularly dsplaceable ,members are disposed on opposite sides of the common rocker shaft, each angularly dsplaceable member engaging one eccentric of the common rocker shaft and in which said shaft is rockable between three positions so that rocking of the shaft between mid-position and one position displaces the valve of one mechanism only while rocking between mid-position and the other adjacent position displaces the valve of the other said mechanism.

5. A fluid pressure control mechanism comprising a housing having four valve mechanisms in side by side relationship, each said valve mechanism comprising supply, operating and exhaust chambers, a hollow longitudinally slidable operating member having a recess formed therein, a passage through said operating member` connecting said operating and exhaust chambers, a pair of connected valves co-axial with and movable by said operating member, one of said valves on the operating side of said valve seat being positioned to be contacted by said operating member to close said passage and the other valve being movable from said valve seat on further movement of said operating member, an angularly dsplaceable member bifurcated at one extremity to form a slot, one branch of said bifurcated member being extended to iit into the recess in said longitudinally dsplaceable operating member, and a common rocker shaft for actuating said valve mechanisms, said shaft being provided with four eccentrics one for each valve member engaging the slot of its respective angularly dsplaceable bifurcated member whereby said member may be actuated from said common rocker member.

6. A iiuid pressure control mechanism comprising a housing having supply, operating and exhaust chambers, a valve seat between said supply and operating chambers, a hollow longitudinally slidable operatingfmemberhaving a recess;` formed therein, a passage through said operating member connecting saidr operating and exhausty chambers`,.a pair'oi connected. valvesco-axiar` with, and movable by said operating member, one of said valves on, the operating side of said valvey seat. being positioned to be contacted by said operating member to close said passage and the other valve being movable' from said valve seat on further movement of. said operating member, an angularly displaceable member bifurcated at one extremiti?`- to` form aI slot, one. branch of said bifurcated member being extended toy iit into the recess iin said longitudinally slid-able operating member and a rocker shaftprovidedl with an eccentric engaging the slot of said' angularly -displvaceable bifucated member, whereby said member may be actuatedto. operate said valves, the said rocker shaft being rockable between three positions and said eccentric is so positioned relative to said slot that the rocking of said shaft between mid-position and one adjacent position operates the valvesA while rocking between the mid-position 'and the other position does not operate. the valves.

7. A u'id pressure control mechanism oomprising' a housing having supply, operating and exhaust chambers, a valve seat between said supply and operating chambers, a hollow longitudinally sl-idab-le operating member having a recess formed therein, aI passage through said operating member connecting said operating and exhaust chambers, a pair of connected valves co-axial with, and movable by said operating member, one

8 of said valves: on the: operating side of said: valve seat: being. positioned to becontacted by said operating` member tol close said passage andthe other vaivebeing movable fromsaid valve seat on further movement of said operating member, an angularly displaceable member bifurcated at. one extremity toiforma Slot, one branch of said bifurcated: member being extended to lit into the recess in said longitudinally slidable operating member and av rocker shaft: provided with an eccentric engaging the slot of saidY arogularlyl displaceable biturcatedz member, whereby.V saidmember may be actuated to operate said valves, said angularly displaceable member having two projecting iingers` remote from the bifurcation extending into contact. with the walls of the exhaust chamber to position said' displaoeable member in said exhaust chamber.,

HENRY WILLIAM TREVASKIS.

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